Originally Posted by Dicko&Sarah
right ive just fitted a 4x4 inlet plenum fuel rail and pressure reg to my 2wd saff but used the 2wd throttle body etc (dont know if different)
The car runs fine but has got what seems like an air leak now, sort of like a loud whistle

it goes away when you rev the car.
i even removed the full thing and put more new gaskets on but still the same
can anybody shed any light please

You want to do a pressure test next me thinks.
Pump the hoses with air (compressor and bung in the inlet pipe) Spray soapy water everywhere round the plenum - look for bubbles. Fix leak, Bob's your uncle.
Si